A precise channeling model is proposed for ion-implantation analysis. This channeling model includes defect scattering effects on the impurity profiles. It is restricted to only a major axial channel for simplicity and is introduced to the two-dimensional Boltzmann transport equation method in order to accurately calculate the impurity profiles. The calculations are in good agreement with experimental values at a wide range of conditions (As+and B+, 5-130 keV, 5 × 1013to 1 × 1015cm-2). Furthermore, it is concluded that more than 2 × 1017cm-3recoiled atoms prevent the ions from channeling in the Si target. Thus, this channeling model is precise enough to use in the design of even shallow-junctioned and fine-structured devices.